AVIS-IBIS

Birds of Indian Subcontinent

How Vegetative Cover Protects Duck Nests from Egg-Eating Birds

Publication Type:Journal Article
Year of Publication:1972
Authors:Dwernychuk, LW, Boag, DA
Journal:The Journal of Wildlife Management
Volume:36
Issue:3
Date Published:1972
ISBN Number:0022541X
Keywords:Corvidae, Laridae, Larus, Larus californicus, Larus delawarensis, Pica, Pica hudsonia, Pica pica
Abstract:The importance of vegetative cover in protecting duck nests from egg-eating birds was evaluated over two seasons on two islands in a lake in central Alberta, Canada. Avian species recorded preying upon the eggs of ducks included ring-billed gulls (Larus delawarensis), California gulls (L. californicus), crows (Corvus brachyrhynchus), and black-billed magpies (Pica pica). Apparently egg pilfering occurred when nests were unattended, mainly during the laying stage. No relationship could be demonstrated between egg loss and amount of screening cover at actual duck nests, possibly because all other factors at the nests were not equal. At artificially placed nests, egg loss was inversely correlated with the amount of overhead cover, suggesting that visibility of eggs was a major factor in their destruction. However, avian predators must have used additional visual cues in locating well-hidden nests, the most likely being disturbed vegetation.
URL:http://www.jstor.org/stable/3799456
Short Title:The Journal of Wildlife Management
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